The invention relates to a digital time division multiplex (TDM) telecommunication network wherein the subscriber terminals are connected in a defined sequence to a common TDM highway and wherein through a central office, from which the TDM highway begins and to which it is returned, the telecommunication data in each pulse frame for subscriber terminals involved in calls are transmitted in the sequence of their connection to the TDM highway. Each data portion is accepted by the first subscriber terminal that has not yet been supplied with information, whereupon the latter immediately thereafter transmits to the central office in outgoing direction the information to be sent by it past subsequent subscriber terminals.
In a similar TDM telecommunication network of known construction (cf. West German patent application P 24 38 199.5-31) the TDM highway constitutes a single unbranched route. A copy of the West German patent application No. P 24 38 199.5- 31 can be found in the application file. A translation of this West German patent application also can be found in the application file. This translation corresponds to U.S. Pat. No. 4,051,328 in which foreign priority was claimed based on West German Patent Application No. P 24 38 199.5-31. This U.S. Pat. No. 4,051,320 was issued on Sept. 27, 1977 to the same inventor and is assigned to the same assignee as the present invention. However, in developing such a system it was learned that even in the region of a central office there may be a need for a branched bus system, particularly, if there are remote groups of terminals. If, as assumed hereinabove, the TDM highway begins from the central office and terminates therein, i.e., if only one looped circuit is provided, the interruption of such a loop at any point means the breakdown of the entire group of terminals served by this loop.
Therefore, it is an object of the invention to provide for a telecommunication network of the type described hereinabove having a branching structure by means of which one can cope with the spatial distribution of the subscriber terminals and wherein complete breakdowns and breakdowns of large regions of such a network configuration are largely avoided.